Reduction of cholesterol greatly lowers the incidence of cardiovascular disease. Thus, it has been reported in JAMA 1984; 251:351-64 that lowering of serum cholesterol levels with drugs prevents heart attacks. Coronary angiographic studies have also demonstrated the benefits of lower serum cholesterol in the prevention of coronary heart disease. See, for example, Levy et al, Circulation, 69:32S-37 (1984). Other studies also reported the benefits of lower cholesterol in slowing the growth of atherosclerotic lesions. See, for example, Blankenhom et al., JAMA, 257:323340 (1987).
The drugs which are being used in these studies are, for example, clofibrate, gemfibrozil, fenofibrate and bezafibrate or a combination of cholestyramine and niacin. These reports clearly support the theory that lowering of serum cholesterol level will retard coronary atherogenesis and therefore reduce the risk of cardiovascular disease.
One of the problems with the therapy described above is that they are all pharmaceutical compounds which tend to require a long course of therapy. Unfortunately, considerable undesirable side effects are experienced by a number of patients.
Several therapeutic approaches for using vitamin E have been proposed. One such approach is described in the articles, "Vitamin E Consumption And The Risk Of Coronary Disease In Women" by Stampfer et al., The New England Journal of Medicine, 328: 1444-9 (1993), and "Vitamin E Consumption And The Risk of Coronary Heart Disease In Men" by Rimm et al., The New England Journal of Medicine, 328: 1450-6 (1993), which disclose that oxidation of low-density lipoprotein (LDL) plays a role in atherosclerosis. It appears that the oxidation of LDL increases their incorporation into the arterial intima which is an essential step in atherogenesis.
Thus, in the foregoing articles, investigators have studied the effect of taking vitamin E and the risk of coronary disease and observed that the use of vitamin E supplements in middle-aged women is associated with a reduced risk of coronary heart disease. Similarly, an association between a high intake of vitamin E and a lower risk of coronary heart disease was also observed in men.
In another study reported in Lancet, 342: 1379-84 (1993), it was observed that high beta-carotene intake reduced the risk of myocardial infarction. Beta-carotene has also been suggested as useful in reducing vascular events in patients with chronic stable angina. See, Gaziano et al., "Beta Carotene Therapy for Chronic Stable Angina," Circulation 82:III, Abstract No. 0796 (1990).
In spite of the foregoing attempts to develop a method for preventing or treating high levels of serum cholesterol and/or lipids, there still exists a need in the art for a composition and method for protecting a mammal, including humans, against high serum cholesterol and lipid levels without the disadvantages and side effects associated with conventional drug therapy.